Device for clamping of buffing and polishing cloths

ABSTRACT

A device for clamping or securing buffing and polishing cloths, such as used on the disks of rotary and vibratory buffing and polishing machines, comprising an outer accommodating member and at least one inner clamping member, the former being made of a material which is stable in shape, such as plastics, while the latter is preferably made of wood which is adapted to swell on effect of a polishing or abrading suspension used in the machine. The outer member has a groove for receiving part of the inner member or members. The members of the clamping device may be circular or rectangular; up to four inner member parts are suggested, particularly in the rectangular embodiment.

United States Patent Poleska et al.

[ 1 Feb.l,l972

[72] Inventors: Horst Poleska; Horst Fleischhauer, both of Rathenow, Germany A. J. Tocci; improved Polishing Device Having Easy Removal Feature and Means for Holding Polishing Pads Without Adhesives, Apr. 3, 1969; RCA Technical Notes; TN. No.823.

Primary Examiner-Walter A. Scheel Assistant ExaminerAlan l. Cantor Atlorney-Tab T. Thein [57] ABSTRACT A device for clamping or securing buffing and polishing cloths, such as used on the disks of rotary and vibratory buffing and polishing machines, comprising an outer accommodating member and at least one inner clamping member, the former being made of a material which is stable in shape, such as plastics, while the latter is preferably made of wood which is adapted to swell on effect of a polishing or abrading suspension used in the machine. The outer member has a groove for receiving part of the inner member or members. The members of the clamping device may be circular or rectangular; up to four inner member parts are suggested, particularly in the rectangular embodiment.

11 Claims, 9 Drawing Figures I 10 I I l l I PATENTEU FEBI m2 3.638.272

sum 1 or 2 FIG. 1

FIG. 2 19' INVENTORS HORST POLESKA HORST FLE ISCHHAUER AGFNT PATENTEDFEBI #912 3,638,272

SHEET 2 OF 2 INVENTORS HORST POLES KA HQRST FLEISCHHAUER BY 0% AGENT DEVICE FOR CLAMPING F BUFFING AND POLISHING CLOTI-IS The invention relates to a device for clamping buffing and polishing cloths upon rotating and vibrating disks employed in the processing of materials while a polishing or abrading suspension is used.

Clamping members had already been disclosed in the shape of rings with tapered inner surfaces, which are pressed upon the disks on which the polishing cloths are spanned; the disks, as a rule, have the same taper on their edges.

To prevent the loosening of these tapered surfaces from one another, and thus the slackening of the cloth, it is also known that the clamping members of spanning rings are made to abut tightly, by means of screws or springs.

Known is also the securing of the cloth by means of a steel band in the form of an annular clamp with a turnbuckle.

Another known design provides an open clamping ring made of spring wire, which snaps over the cloth into a corresponding annular groove in the polishing disk.

In order to avoid structural parts susceptible to corrosion, an attempt has already been made to affix a border to the edge of the round cloth with a cord inserted in said border. The thus prepared cloth is then extended over the polishing disk, and is tied up on the underside thereof in the manner of a pouch.

The known structures have various drawbacks, in particular when they are to be used for vibrating disks or when abrading and/or polishing agents are utilized. Thus, for example, clamping elements with a tapered engagement may loosen through concussion if vibrating disks are used.

Resilient clamping devices must be very strongly constructed, owing to the load on the cloth through thrust forces while the specimen or workpiece is acted upon, or through tensile stresses in the cloth, and such devices may be frequently fitted on, and removed, only with difficulty. Based on experience, such a clamping arrangement is not sufficiently secure.

Clamping devices with additional screw joints, which are extended over a greater width of the disk edge, are very costly and offer little security in the case of cloths with different thicknesses.

Clamping or retaining mechanisms with special designs of the round cloth, such as with a border and a pulling cord, either require constant supplemental supply from the manufacturer or the unwarranted expense on the users part if he makes these parts himself.

Another drawback of all clamping devices made of metal is that, where abrading or buffing suspension agents are used, additional expense is necessary in order to provide for sufficient protection against corrosion.

It is one of the major objects of this invention to substantially eliminate the aforedescribed drawbacks.

Consequently the invention is based on the task of finding a simple, corrosion-resistant clamping element or device which works safely also in the case of cloths with varying thicknesses when the processing is done with abrading or polishing agents.

According to important features of the invention this task is accomplished in that an open ring, or one consisting of a number of parts, made of a swellable material, is inserted into an outer ring which is stable in shape, and in that the inner ring is preferably of wood and the outer ring is preferably made of plastics. I

According to the invention the outer or accommodating member and, correspondingly thereto, the inner or clamping member may be given any shape which corresponds to that of the polishing disk and other than circular, for example, the shape ofa rectangle.

The inventive clamping device basically consists of two simple parts, namely the outer member with a groove on the inside thereof to accommodate the inner member, and the inner member itself. These members may be produced at relatively small cost, and the effectiveness of the inventive device surpasses all hitherto known designs of clamping devices.

Other objects, features and structural details of this invention will become apparent from the further description when read in conjunction with the accompanying drawings, showing several embodiments of the invention, and wherein FIG. I is a schematic, partly sectional elevational view of a buffing device with a rotating disk, and one embodiment of the clamping device according to the invention applied thereto;

FIG. 2 is a view similar to that of FIG. 1, ofa buffing device with a vibrating disk, and another embodiment of the clamping device according to the invention attached thereto;

FIG. 3a is a partly cutoff view in perspective of an outer accommodating ring having an annular groove on the inside thereof;

FIG. 3b is a similar view ofan inner clamping ring;

FIG. 3c is a ring similar to that shown in FIG. 3b but subdivided, for example, into four parts;

FIG. 4 is a perspective view showing the rings of FIGS. 30 and 3b assembled for use, and constituting the first exemplary embodiment of the inventive clamping device, as may be used in the setup of FIG. 1;

FIG. 5a is an alternative outer member, rectangular in shape, performing the same function as the ring of FIG. 30;

FIG. 5b shows four inner member parts, similar in function to those of FIG. 30, to be inserted in the outer member of FIG. 5a; and

FIG. 6 is a perspective view showing the members of FIGS. 51: and 5b assembled for use, constituting the second embodiment of the clamping device, as may be used in the machine of FIG. 2.

Before describing the buffing and polishing devices or machines as shown in FIGS. 1 and 2, as a matter of example only, the inventive clamping devices will be explained.

The first embodiment of the inventive clamping device is illustrated in FIGS. 3a, 3b and 4, and can be used in the machine setup as exemplified in FIG. 1, to be described somewhat later. An outer or accommodating ring member 1 is shown which has an inner annular groove 1', preferably of rectangular shape, and which is advantageously made of a plastic material, for example, polyvinyl chloride, a polyamide or polyethylene, for reasons of protection against corrosion, e.g., by the abrading or polishing suspension used during the process. The outer member has to be stable in shape, that is free from deformation when the inner member (to be described hereunder) swells on effect of the applied suspension.

In the groove 1' there is inserted a strip or band-shaped member 2 made of a swellable material, such as preferably wood. This member 2, constituting an inner or clamping member, is bent or otherwise preshaped so as to fit into the groove 1. Themember 2 is preferably slit at one point so as to provide for resilience during and after being inserted in the member 1.

The alternative of FIG. 30 shows an inner member which is subdivided into, say, four parts, as shown at 2a, 2b, 2c and 2d, insertable in the outer member 1 in a symmetrical manner. There may of course be a smaller number of sections or parts, e.g., two or three, to be fitted into the groove 1 of outer member 1. Preferably the innermost edge of the inner member 2 (or 2a 2d) protrudes inwardly from the groove 1' of the outer member 1 by about one-half of the width of the inner member.

The cross sections of the groove in the outer member and of the inner member of member sections is preferably rectangular, as shown, although other cross sections could be used as long as they include a substantially annular inner wall adapted to clamp the cloth when applied to the disk of the buffing and polishing machine.

A machine setup in which the first embodiment of the inventive clamping device can be used is shown in FIG. 1. The machine operates with a rotating disk driven by an electric motor. The clamping device, including the members 1 and 2, surrounds a buffing and polishing cloth 5 which is tightly applied to the outer surface of a disk 6. A suspension or liquid is generally used, as shown at 7 above the inner member 2, for

assisting the polishing process, the overflow and/or the excess splashed around by the centrifugal force may be collected as exemplified at 8.

A machine housing is schematically shown at 9, with an upper hood portion 9a protecting the rotating disk structure (elements 1, 2, 5, 6 and 7). At 9b an optional release valve is shown for the surplus suspension that may be recovered from the area 8 and reused by administering the same, by conventional method (e.g., a dripping conduit), to the buffing and polishing area above and around the disk 6 having the cloth thereon. The housing portion 9a is preferably provided with a hinged or otherwise openable cover portion 9, as schematically shown, which allows access to the specimens or workpieces treated in contact with the surface of the rotating disk. The opening is mostly needed for manual work; it is usually closed for automatic operation of the machine. A conventional motor 10 is provided for actuating the machine by rotating the above-mentioned disk structure.

In vibration polishing with more than one pair of parallel outer surfaces the disk may have a shape other than circular, as used for rotary polishing, such as for example rectangular. correspondingly the clamping device of the invention, according to its second embodiment, may have a similar rectangular configuration. This is shown in FIGS. 5a, 5b and 6, for use in the machine setup as exemplified in FIG. 2. In this case an outer or accommodating member is shown at 11, with an inner groove 11, for receiving one or more strip-shaped inner members such as shown in FIG. 6b at 12a, 12b, 12c and 12d (it should be noted that a one-piece inner member fitting the outer member 11 has not been illustrated although it is entirely compatible with the other elements if resiliently fitted into the groove 11).

Here again the outer member 11 is made preferably of plastics and the inner members 12a of wood so as to provide the desired corrosion resistance, as well as the required stable and swellable properties, respectively.

FIGS. 3a and 4, as well as 5a and 6 show, as a matter of example, symmetrically profiled outer members 1 and 11, respectively. The invention also provides for cross sections which are asymmetrical with respect to the inner groove, as shown in FIG. 2 which illustrates the machine setup for using the second embodiment of the inventive clamping device. This machine operates with a vibrating rather than a rotating disk, as will be explained hereinafter.

A buffing cloth 15 is stretched about a disk 16. The polishing or abrading suspension or other agent used to assist in the buffing and polishing process is applied (by conventional means) to the top of the cloth 15, as shown at 17. The somewhat raised sidewalls of the outer member 11 constitute a potlike recess or area in which the suspension is retained. It can be seen from FIG. 2 that the inner member parts 12b, 12d

. constitute at least part of the bottom of said recess by providing a liquidtight seal about the vibrating disk and cloth structure 15, 16, etc. Optionally a receptacle may be provided (as shown in FIG. 1 at 8) for receiving excess suspension, although this is usually not required in vibratory polishing machines as shown in FIG. 2.

In this setup a machine housing is shown at 19, with an upper portion 19a lodging the vibrating disk structure (elements 11, 12b, 12d. 15, 16 and 17). The housing portion 19a is preferably provided with a hinged portion or cover 19' (partly broken away), allowing access to the machine, as has been explained before. At 190, symmetrically disposed resilient supports or legs (for example, in the form of leaf springs) are shown for the vibratory arrangement, set into movement by an AC fed pair of armatures or coils 10, 10" (shown as a matter of example only, these being conventional elements in machines of this kind). FIG. 2 actually shows two of a set of three symmetrical, resilient supports while, it will be understood by those skilled in the art, two, four or more such supports or legs may be provided.

It will be understood from the preceding description that the wooden members 2 or 2a 2d or 12d begin to swell as soon as they come in contact with the suspension used in the buffing and polishing machines. The cloth 5 or 15 is thus tightly clamped or pressed against the edges ofthe disk 6 or 16 since the outer members 1 or 11 are not subject to deformation so that the expansion is exerted substantially in the inward direction (that is toward the center of the disk).

In the inventive clamping devices, wood has been mentioned as a preferred material for the swellable inner or clamping members. It should be noted however that suitable plastics are also being considered, providing the necessary corrosion resistance, and at the same time applying the required clamping action to the cloth fitted to the disk.

The inventive clamping device is forcefully coupled with the disk structure, and it performs the same motions (rotation or vibration) as the disk and cloth assembly.

We claim:

1. A device for clamping buffing and polishing cloths, such as in rotary and vibratory buffing and polishing machines, the device comprising, in combination, a supporting disk forming part of the machine proper, an outer accommodating member made of a material which is substantially stable in shape, hav- 1 ing an inner diameter which is larger than the outer diameter of said disk, and being provided with an inner groove, and at least one inner clamping member made of a swellable material, adapted to be inserted in said groove of the outer member and protruding therefrom in inward direction, into contact with said disk, for securely clamping the cloth which is applied between said at least one inner member and said disk.

2. The device as defined in claim 1, wherein the innermost edge of said at least one inner member protrudes inwardly from said groove of the outer member by about one-half of the width of said at least one inner member.

3. The device as defined in claim 1, wherein the cross sections of said groove of the outer member and of said at least one inner member are substantially rectangular and complementary.

4. The device as defined in claim 1, wherein the material of said outer member is plastic, for example polyvinyl chloride, polyamide or polyethylene, substantially free from deformation on the effect of moisture.

5. The device as defined in claim 1, wherein the material of said at least one inner member is wood, adapted to swell on effect of a polishing or abrading suspension used in the machine.

6. The device as defined in claim 1, wherein both said outer and said inner members are substantially circular in shape.

7. The device as defined in claim 1, wherein both said outer and said inner members are rectangular in shape.

8. The device as defined in claim 1, wherein portions of said inner and said outer members define therebetween a potlike recess for holding a polishing or abrading suspension used in the machine, and wherein said at least one inner member and portions of said disk constitute the bottom of said recess.

9. The device as defined in claim 8, further comprising a housing, portions thereof serving as a receptacle for excess suspension, and means to drain the suspension.

10. The device as defined in claim 1, wherein said at least one inner member consists of at least two complementary parts.

11. The device as defined in claim 10, wherein four parts are provided in said at least one inner member in substantially symmetrical arrangement. 

1. A device for clamping buffing and polishing cloths, such as in rotary and vibratory buffing and polishing machines, the device comprising, in combination, a supporting disk forming part of the machine proper, an outer accommodating member made of a material which is substantially stable in shape, having an inner diameter which is larger than the outer diameter of said disk, and being provided with an inner groove, and at least one inner clamping member made of a swellable material, adapted to be inserted in said groove of the outer member and protruding therefrom in inward direction, into contact with said disk, for securely clamping the cloth which is applied between said at least one inner member and said disk.
 2. The device as defined in claim 1, wherein the innermost edge of said at least one inner member protrudes inwardly from said groove of the outer member by about one-half of the width of said at least one inner member.
 3. The device as defined in claim 1, wherein the cross sections of said groove of the outer member and of said at least one inner member aRe substantially rectangular and complementary.
 4. The device as defined in claim 1, wherein the material of said outer member is plastic, for example polyvinyl chloride, polyamide or polyethylene, substantially free from deformation on the effect of moisture.
 5. The device as defined in claim 1, wherein the material of said at least one inner member is wood, adapted to swell on effect of a polishing or abrading suspension used in the machine.
 6. The device as defined in claim 1, wherein both said outer and said inner members are substantially circular in shape.
 7. The device as defined in claim 1, wherein both said outer and said inner members are rectangular in shape.
 8. The device as defined in claim 1, wherein portions of said inner and said outer members define therebetween a potlike recess for holding a polishing or abrading suspension used in the machine, and wherein said at least one inner member and portions of said disk constitute the bottom of said recess.
 9. The device as defined in claim 8, further comprising a housing, portions thereof serving as a receptacle for excess suspension, and means to drain the suspension.
 10. The device as defined in claim 1, wherein said at least one inner member consists of at least two complementary parts.
 11. The device as defined in claim 10, wherein four parts are provided in said at least one inner member in substantially symmetrical arrangement. 